Our Pro Artist Canvas Boards are made from premium, ultra-smooth 100% Cotton, are acid free, triple primed and ready to work with right out of the package. 20 boards come in this pack of bulk canvases for painting, each board is individually wrapped in protective cellophane to keep them clean, they are ultra-durable and won't bend easily or warp and are ideal to be used with a variety of media including oils, tempera, acrylic paints, markers and many more to produce professional quality art. PLEASE NOTE: If you are working with pouring paints, we do not recommend these boards as they are not wells suited to that medium, we suggest our Stretched Canvas Panels which are are ideal handle the needs of pour paint work. We are a small family owned American business committed to producing professional grade art supplies designed for free-spirited crafters. We proudly stand behind the quality of all our products and strive to set ourselves apart by providing exceptional customer service. If you have any questions on the details of our products or how to use them, just reach out! We are here to help out our fellow crafters in any way we can.